At some social networking services, a user will have a profile and an associated content stream that are accessible (e.g., for viewing and/or posting) by (1) the user and (2) other users or entities that the user follows, according to the settings of an access control list (ACL) controlled by the user and maintained by the social networking service.
Similarly, some social networking services have implemented authorization protocols so that a user of such a service can share data, including content and access control list (ACLs), in a limited fashion with other software services (e.g., a software service hosting an online publication) without requiring the user to hand out his/her credentials (e.g., username and password). Instead, the other software services receive a username-pas sword token of limited duration and scope.